1. Field of the Invention
The invention relates generally to pipelines and more particularly to a system and method for automatically guiding a pair of pipe sections into alignment so that the flanges at the end of the pipe sections can be secured together.
2. Related Art
Pipelines are commonly used to transport oil and other hydrocarbons. Because of the enormous quantities of oil and/or hydrocarbons which need to be transported in this manner, the pipelines typically have relatively large diameters and correspondingly thick walls.
Pipelines of this type are typically constructed by coupling a series of pipe segments, or sections, together to form a single conduit. Often, the pipe sections include a flange at each end which can be coupled to a similar flange of another pipe section. For example, the pipe sections may utilize standard ANSI flanges which are aligned and then bolted together.
Because of the scale of these pipelines, it may be very difficult to align the flanges of adjoining pipe sections so that they can be bolted together. Often, a worker is required to assist in the coupling of two pipe sections by manually guiding the pipe sections together so that they are properly aligned. This can be extremely dangerous because of the weight of the pipe sections, and the worker could easily be injured, or even killed.
One or more of the problems outlined above may be solved by the various embodiments of the invention. Broadly speaking, the invention comprises an alignment tool for guiding two pipe flanges into alignment so they can be secured together, as well as systems and methods for using the alignment tool.
In one embodiment, the alignment tool comprises an alignment guide connected to an attachment body. The alignment guide, when attached to a pipe flange, extends outward from the periphery of the flange at an angle which is about 45 degrees from the axis of the flange. The alignment tool has a pair of alignment pins which are configured to be positioned in the bolt holes of the flange. In one embodiment, the alignment tool includes several set screws which are opposed to the alignment pins. When tightened, the set screws contact the outer edge of the flange and secure the flange against the alignment pins. One or more of the alignment pins which extend through bolt holes of the first flange and beyond the face of the flange so that they can engage one of the bolt holes of a second flange and thereby maintain rotational alignment of the flanges. The alignment pin may comprise a spring-loaded, telescoping pin which, when the flanges are not rotationally aligned, is compressed and does not extend beyond the face of the first flange, and when the flanges are rotationally aligned, extends beyond the face of the first flange to engage a bolt hole of the second flange.
In another embodiment, a system comprises a first flange and a plurality of alignment tools coupled to the first flange. Each of the alignment tools has an alignment guide extending axially forward and radially outward from the periphery of the first flange. The alignment tools constrain the movement of the second flange toward a position which is aligned with the first flange as the second flange becomes closer to the first flange.
In another embodiment, a method comprises attaching a plurality of alignment tools to a first flange so that the alignment guides of the tools extends radially outward and axially forward from the first flange. A second flange is positioned between the alignment guides and moved generally toward the first flange. As the second flange approaches the first flange, the alignment guides force the second flange to move toward an aligned position with respect to the first flange. When the second flange comes into contact with the first flange and/or the alignment pins extending through the first flange, the second flange is rotated until the alignment pins engage the bolt holes of the second flange and prevent it from rotating further. The flanges are now aligned both axially and rotationally. The first and second flanges are then maintained in aligned positions by installing bolts in one or more of the corresponding bolt holes of the flanges. After the alignment tools are removed, the remainder of the bolts can be installed in the flanges and tightened to secure the coupled flanges.